Cooling circuit pump for a motor vehicle

ABSTRACT

The invention relates to a cooling circuit pump for a motor vehicle, having a stator which is arranged in a motor housing ( 14 ) and in which a rotatably mounted rotor is received. It is proposed that the stator ( 12 ) is received in the motor housing ( 14 ) in a positively locking manner.

The invention relates to a cooling circuit pump for a motor vehicle.

The German patent publication DE 10 2009 028 144 A1 discloses a coolingcircuit pump for a motor vehicle, the former having a hydraulic part aswell as an electric motor. When such water pumps are used in theautomotive field, said pumps are exposed to considerable vibration andtemperature loads. This results, for example, during use as a so-calledauxiliary water pump which increases the climate comfort in the motorvehicle, improves the flow of the coolant and supports the heatingcircuit. In so doing, the use of residual heat is facilitated when theengine is turned off. It is known from the prior art how to fasten thestator of the electric motor to the motor housing by means of screw oradhesively bonded connections.

SUMMARY OF THE INVENTION

It is the aim of the present invention to mount the stator of theelectric motor such that said stator is sufficiently fixed when inertiaforces resulting from vibration loads occur and is simultaneously ableto compensate for the dimensional tolerances caused by temperature.

In contrast to the solutions known to date, it is now proposed accordingto the invention that the stator is received in the motor housing in apositively locking manner. As a result, complicated production equipmentis no longer required as is the case for bonding or screwing operations.

The stator which is constructed from a laminated core is preferablyfastened by means of a snap hook device on or in the motor housing.

To this end, snap hooks are disposed on the inside of the laminated coreradially around the circumference of the motor housing in a distributedmanner, said snap hooks engaging around the laminated core in apositively locking manner with the aid of latching lugs formed on theends thereof. The snap hooks are thereby attached to a support ring,wherein support ring and snap hooks are preferably configured as onepiece with the motor housing, e.g. manufactured by means of an injectionmolding process.

A tolerance compensation element is disposed between support ring andthe laminated core of the stator, which element, as previouslymentioned, ensures that expansions due to temperature can be absorbed.In addition, the tolerance compensation element allows the stator to beeasily mounted in the motor housing.

In a second advantageous embodiment, the snap hooks are fastened to arotor can.

A further modified embodiment consists of the laminated core having astep or ledge on which the latching lugs of the snap hooks engage.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a cross section through an electric motor of a coolingcircuit pump.

FIG. 2 shows a corresponding top view of the electric motor.

FIG. 3 shows a cross section through an electric motor of a coolingcircuit pump in a second embodiment and

FIG. 4 shows a cross section through an electric motor of a coolingcircuit pump in a third embodiment.

DETAILED DESCRIPTION

In FIG. 1, an electric motor is depicted in cross section, whichpreferably is used in cooling circuit pumps in the automotive field.Design and function of such cooling circuit pumps are generally known,for example from the German patent publication DE 10 2009 028 144 A1cited at the beginning of the application. The disclosure content ofsaid patent publication will be explicitly referred to if necessary.

Only the components of the cooling circuit pump are however describedbelow which are necessary to explain the invention. The stator 12comprising a laminated core is received in a motor housing 14 of theelectric motor 10. In order to mount the stator 12 in a positivelylocking manner, six snap hooks 16 are provided which are uniformlydistributed on the circumference of the motor housing 14. The snap hooks16 attach thereby in the region of a support ring 18 which is preferablymanufactured as one piece together with the snap hooks 16 and the motorhousing 14 in an injection molding process. The snap hooks 16 havecorresponding latching lugs 20 on the free ends thereof, said latchinglugs engaging in a positively locking manner around the uppermostlamella 13 of the laminated core in the installed state; thus enablingthe entire laminated core to be reliably fixed in the motor housing 14.A tolerance compensation element 22 which is correspondingly matched tothe diameter of the lamellae or the support ring 18 is disposed betweensupport ring 18 and the lowermost lamella 15 of the laminated core, saidtolerance compensation element being embodied as an elastomer ring or asa metal corrugated washer.

Because the electric motor 10 has to be reliably sealed off from thehydraulic part of the cooling circuit pump during installation, a rotorcan or pot 24 is introduced into the motor housing 14 as depicted inFIG. 1 which is concentrically enclosed by the stator 12 on the outsideand the interior 26 of which accommodates the rotor (not depicted) ofthe electric motor 10.

The assembly takes place by the mating of the stator 12 and the engagingof the latching lugs 20 on the uppermost lamella 13 of the laminatedcore after excessive pressure has been applied to the elastic tolerancecompensation element 22. In comparison to a radial mounting of thestator, for example by means of screws or adhesive bonding, the axialbracing of the rotor 12 achieved in the process does not have to absorbany tolerances in the circumferential direction.

In a second exemplary embodiment pursuant to FIG. 3 in which identicalcomponents are provided with the identical reference numerals, the snaphooks 16, in contrast to the first exemplary embodiment, are configuredon or fastened to a flange ring 28 formed from the pot 24.

In a third exemplary embodiment (see FIG. 4), in which identicalcomponents are once again provided with identical reference numerals,the length of the snap hooks 30 and thus the required tolerancecompensation is reduced in contrast to the first and second exemplaryembodiment. In this case, the laminated core of the stator 12 isconfigured in a stepped manner in the axial extension thereof, and thelatching lugs 32 of the snap hooks 30 engage on a ledge 34 in theassembled state. The ledge 34 is thereby formed by means of theselection of two different sheet metal ring thicknesses.

The mounting of a stator described above is, of course, not limited tothe installation in a coolant pump but can be universally used forelectric motors in a variety of applications.

1. A cooling circuit pump for a motor vehicle, having a stator (12)which is arranged in a motor housing (14) and in which a rotatablymounted rotor is received, characterized in that the stator (12) isreceived in the motor housing (14) in a positively locking manner. 2.The cooling circuit pump according to claim 1, characterized in that thestator (12) comprises a laminated core which is mounted by means of asnap hook device (16, 30) in the motor housing (14).
 3. The coolingcircuit pump according to claim 2, characterized in that snap hooks (16,30) are disposed on an inside of the laminated core radially around acircumference of the motor housing (14) in a distributed manner, whereinlatching lugs (20, 32) formed on an end of the snap hooks (16, 30)engage around the laminated core in a positively locking manner.
 4. Thecooling circuit pump according to claim 3, characterized in that thesnap hooks (16) are attached to a support ring (18).
 5. The coolingcircuit pump according to claim 4, characterized in that a tolerancecompensation element (22) is disposed between the support ring (18) andthe laminated core.
 6. The cooling circuit pump according to claim 3,characterized in that the snap hooks (16) are fastened to a rotor can(24) disposed between the stator (12) and the rotor.
 7. The coolingcircuit pump according to claim 3, characterized in that the laminatedcore of the stator (12) has a step or a ledge (34) in an axial extensionthereof, on which the latching lugs (32) of the snap hooks (30) engage.8. The cooling circuit pump according to claim 3, characterized in thatthe snap hooks (16) are attached to a support ring (18) which ismanufactured as one piece together with said snap hooks (16) and themotor housing (14).